Welder not turning on - Learning
Hello people. I trying to repair my welding machine oerlikon citomig 180mp hpf and there is a little board with blown stuff.The problem is i cant identify the value of the blown resistor and diode. Any suggestion?
-
-
I guess you got 2 choices.
A: Replace the board as a whole
B: Maybe you are lucky and find the datasheet from that 8pin DIP IC (gate drive) and see what the example circuit has to offer.
Chances are you going to need that IC anyway, since the Mosfet blew and shorted to the gate drive. -
The 8pin IC is UC3843BN. And yeah the mosfet is shorted source to gate.Comment
-
The worst thing is the company went bankrupt and there is no more spare parts.Comment
-
Pin 6 is VCC so that bigger resistor can’t be that high in value. Pin 7 is the destroyed gate drive with the smaller resistor and diode. The diode isn’t that critical but the gate drive resistor doesn’t have to be bang on, but should be as close as we can get it.
What was the mosfet? Upload a straight shot picture of the board from top.Comment
-
I removed the heat sink and the mosfet so u can see more and also tried to clear the gunk. I can write a diagram if you want me to.
Note: D201 is also blown and from bottom side R209 too.Attached Filesif you find these attachements useful please consider making a small donation to the site
Comment
-
-
almost forgot the mosfet is K3878
Attached Filesif you find these attachements useful please consider making a small donation to the site
Comment
-
-
The gate drive resistor is usually something between 0 and 100ohm, the gate drive diode is probably something similar as an RB160L60. The diodes trough hole I'd put something 1A, 600V or better ultra fast in there. The gate resistor and the diode are there to slow the Mosfet down and prevent ringing.
As for R209, I am not sure where it goes to what pin in the IC.
Drawing a supporting schematic would simplify things for sure.Comment
-
I just pulled the sales flyer for it and it has Lincoln Electric on the bottom of it. So you should be able to get a spare board as that company shouldn't be bankrupt.
Try these guys in Slovakia :
AIR LIQUIDE WELDING CENTRAL EUROPE S.R.O.
Hlohovecká 6 - 951 41 NITRA - LUŽIANKY
Tel.: +421 37 692 4610 - Fax: +421 37 651 28 04
https://www.wecs-ltd.co.uk/wp-conten...erlikon_en.pdfComment
-
already tried but its closed and there is other company
Air Liquide Welding Ltd. - Google MapsComment
-
i already working on the schematic i need one more day to finish it
Comment
-
Very good!Comment
-
Comment
-
Comment
-
Comment
-
Comment
-
Let me know please if its readable. Thank you
Comment
-
I need somehow to guess the values of : R209 , R208 , R207 , D203.
And replacement for : D201 , i found this diode was BYV26EComment
-
It is starting to make a bit of sense now how this works. Good drawing! Here is with what I roughly came up with. I am not sure on the exact value of R209 and R207. The BYV26E is better than the 1n4937 that I guessed on D201.
example circuits show R207 as 10k Ohm… as 10R0?Attached Filesif you find these attachements useful please consider making a small donation to the site
Last edited by CapLeaker; 05-19-2024, 05:34 PM.Comment
-
-
Hello everyone
I attach a schematic and teardown photos for the DoCreate DHJ567 handheld spot welder. I bought this welder for temporary use while my supercapacitor welder was waiting for replacement parts. It cost only £24, though there is a screenless version available for £17.
Performance: The absolute maximum it can handle appears to be 0.15mm of pure nickel. Reliability was not great - welds were very inconsistent, ranging from weak attachment to burning through the strip. However, I was able to build a 5S2P pack without losing any cells. It's a bit difficult getting... -
Hello people. I trying to repair my Sencor TV. No standby light, not tuning on what i found there is 6V where 12V should be and 8V where 16V should be. Any suggestion?05-18-2024, 01:40 PM -
This is my own welder, that blew up while welding. There is no warranty on it. Purchased it a year ago, sealed box from Craigslist.
It worked great until now, about a year.
What I have found is a blown trace next to the main capacitors, it seems like also got damaged the SMPS IC, output MOSFET and a 1 Ohm resistor to the ground from the MOSFET.
After replacing these components, the relay, fans turn on and it sounds like it's working, but there is no output voltage for the welder, LEDs do not turn on.
So there are more components that are damaged.
I'm having a hard... -
I had my Quadra 840AV (which I recapped and had working) plugged in for some time without using it and randomly decided to turn it on today. Unfortunately it did not turn on. After checking the PSU, I found out I was not getting anything from 12V, only from the 5V rail. After a few minutes, I removed the PSU and plugged it back in the electrical outlet and it suddenly started making a weird sound and soon after smoke started coming out. I quickly unplugged it. I opened it up but on first instance I didn't see anything out of the ordinary really. I later turned it back on and one of the MOVs blew...12-22-2024, 05:07 AM -
I have a battery operated tab welder and the battery does not have enough current for the battery tab welder because after about 30 welded it does not have the same current output it voltage has gone down by at least 0.500 volts or maybe a more than that
I can fit 21700 battery cells in the enclosure it is very tight fit for four of them that are 35 amp high current capacity 35X4=140 high current output this should work a lot better than what is installed right now
I tested the battery cells there are installed right now and they are testing good with no issues that I...
Comment